If $x \bigtriangleup y = 7y+2$ and $x \oplus y = 3x-y$, find $(1 \bigtriangleup -2) \oplus 2$.
Explanation: First, find $1 \bigtriangleup -2$ $ 1 \bigtriangleup -2 = (7)(-2)+2$ $ \hphantom{1 \bigtriangleup -2} = -12$ Now, find $-12 \oplus 2$ $ -12 \oplus 2 = (3)(-12)-2$ $ \hphantom{-12 \oplus 2} = -38$.